Leather treatment

Abstract

An improved method for dying leather with propylene glycol monomethyl ether (PGME) systems comprising adding polyacrylate resin base, C3 and C4 alcohols, and n-butyl acetate and negating the need for teflon dispersions, dibutyl phthalate, and improves the dye penetration, hastens the flash times, improve the dust free time, and improves the tape time.

Description

[0001] This application is a continuation-in-part of U.S. application Ser. No. 10 / 158,441 filed May 30, 2002.[0002] 1. Field of the Invention[0003] This invention relates to leather coating compositions, particularly those compositions for dyeing, staining, or otherwise modifying the color of leather.[0004] 2. Background of the Prior Art[0005] In recent years numerous advancements have been made in processes for coloring leather. U.S. Pat. No. 5,354,341 disclosed a mixture of at least 2 metal-free dyes having a trichromatic formulation that enhances the brilliance of the finished color on the leather. The dyes carry a single sulfo or carboxyl group and molecular weight of 450 to 700. The dyeing time routinely requires 30 to 180 minutes to dry.[0006] U.S. Pat. No. 5,376,147 likewise disclosed improvements in the trichromatic technique by employing dyes having two sulfo or carboxyl groups and molecular weights between 790 to 1100, but the dyeing process still required 30 to 180 minute...

AI Technical Summary

Problems solved by technology

Again, however, the coated leather required 120 seconds to dry at 90.degree. C.

Also, the quality of the finish is not as soft and natural as desired, even though dibutyl phthalate is used.